Upon getting out of the car, I looked eastward toward the mountains directly east of Tucson. Some distance away, yet on the city side of the mountains, I witnessed a single white light ascending at an almost vertical angle. Upon reaching an altitude approximate to that of most private (Cessna type) aircraft, it flashed once as though reorienting and took off at an extremely high rate of speed at an approximately 40 degree angle toward orbit. It then winked out and disappeared.